Patient-Specific Glenoid Depth Control

ABSTRACT

A system for reaming a bone including a guiding wire configured to be attached to the bone; a tubular depth guide configured to cover at least a portion of the guiding wire, the tubular depth guide including a first end configured to abut the bone, and a second end opposite the first end; a reaming device including an elongate recess therein that extends between a reaming tool of the reaming device and an interior of a handle of the reaming device, wherein the elongate recess is configured to receive each of the guiding wire and depth guide therein, the elongate recess includes a reduced diameter section that defines a shoulder, and the shoulder is designed to abut the second end of the tubular depth guide to control a depth to which the bone is reamed.

INTRODUCTION

In shoulder arthroplasty various guides and instruments are used todetermine an alignment axis and guide an implant for anatomic or reverseshoulder arthroplasty. The present teachings provide variouspatient-specific and other instruments for use in shoulder arthroplasty.

SUMMARY

The present teachings provide various patient-specific instruments foranatomic and reverse shoulder arthroplasty.

Specifically, the present teachings provide a system for reaming a boneincluding a guiding wire configured to be attached to the bone; atubular depth guide configured to cover at least a portion of theguiding wire, the tubular depth guide including a first end configuredto abut the bone, and a second end opposite the first end; a reamingdevice including an elongate recess therein that extends between areaming tool of the reaming device and an interior of a handle of thereaming device, wherein the elongate recess is configured to receiveeach of the guiding wire and depth guide therein, the elongate recessincludes a reduced diameter section that defines a shoulder, and theshoulder is designed to abut the second end of the tubular depth guideto control a depth to which the bone is reamed.

The present teachings also provide a method for reaming a bone thatincludes attaching a guiding wire to the bone; covering at least aportion of the guiding wire with a tubular depth guide, the tubulardepth guide including a first end configured to abut the bone, and asecond end opposite the first end; reaming the bone with a reamingdevice, the reaming device including an elongate recess therein thatextends between a reaming tool of the reaming device and an interior ofa handle of the reaming device, wherein the elongate recess isconfigured to receive each of the guiding wire and depth guide therein,the elongate recess includes a reduced diameter section that defines ashoulder, and the shoulder is designed to abut the second end of thetubular depth guide to control a depth to which the bone is reamed.

Further areas of applicability of the present teachings will becomeapparent from the description provided hereinafter. It should beunderstood that the description and specific examples are intended forpurposes of illustration only and are not intended to limit the scope ofthe present teachings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present teachings will become more fully understood from thedetailed description and the accompanying drawings.

FIG. 1 is an exploded view of a prior art implant for reverse shoulderarthroplasty;

FIG. 2 is an environmental view of the prior art implant of FIG. 1;

FIG. 3A is an environmental view illustrating a guiding pin used duringreaming in reverse shoulder arthroplasty;

FIG. 3B is an environmental view illustrating a guiding pin afterreaming in reverse shoulder arthroplasty;

FIG. 4 is a perspective view of a prior art implant for anatomicshoulder arthroplasty;

FIG. 5 is perspective bottom view of a patient-specific glenoid guidefor reverse and anatomic shoulder arthroplasty according to the presentteachings;

FIG. 6 is perspective view of a glenoid including a guiding pin and adepth guide used during reaming of the glenoid;

FIG. 7 is a perspective view of the depth guide illustrated in FIG. 6;

FIG. 8 is cross-sectional view of a reamer during reaming of the glenoidwith the guiding pin and depth guide illustrated in FIG. 6 receivedtherein; and

FIG. 8A is a close-up of FIG. 8 illustrating a portion of the reamerwith the guiding pin and depth guide received therein.

Corresponding reference numerals indicate corresponding parts throughoutthe several views of the drawings

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is in no wayintended to limit the present teachings, applications, or uses.

The present teachings generally provide patient-specific surgicalinstruments that include, for example, alignment guides, drill guides,and other tools for use in shoulder joint replacement, shoulderresurfacing procedures and other procedures related to the shoulderjoint or the various bones of the shoulder joint, including the glenoidface or cavity of the scapula, the humeral head and adjacent shoulderbones. The present teachings can be applied to anatomic shoulderreplacement and reverse shoulder replacement. The patient-specificinstruments can be used either with conventional implant components orwith patient-specific implant components and/or bone grafts that areprepared using computer-assisted image methods according to the presentteachings. Computer modeling for obtaining three-dimensional images ofthe patient's anatomy using medical scans of the patient's anatomy (suchas MRI, CT, ultrasound, X-rays, PET, etc.), the patient-specificprosthesis components and the patient-specific guides, templates andother instruments, can be prepared using various commercially availableCAD programs and/or software available, for example, by Object ResearchSystems or ORS, Montreal, Canada.

The patient-specific instruments and any associated patient-specificimplants and bone grafts can be generally designed and manufacturedbased on computer modeling of the patient's 3-D anatomic image generatedfrom medical image scans including, for example, X-rays, MRI, CT, PET,ultrasound or other medical scans. The patient-specific instruments canhave a three-dimensional engagement surface that is complementary andmade to substantially mate and match in only one position (i.e., as asubstantially negative or mirror or inverse surface) with athree-dimensional bone surface with or without associated soft tissues,which is reconstructed as a 3-D image via the aforementioned CAD orsoftware. Very small irregularities need not be incorporated in thethree-dimensional engagement surface. The patient-specific instrumentscan include custom-made guiding formations, such as, for example,guiding bores or cannulated guiding posts or cannulated guidingextensions or receptacles that can be used for supporting or guidingother instruments, such as drill guides, reamers, cutters, cuttingguides and cutting blocks or for inserting guiding pins, K-wire, orother fasteners according to a surgeon-approved pre-operative plan.

In various embodiments, the patient-specific instruments of the presentteachings can also include one or more patient-specific tubular guidesfor receiving and guiding a tool, such as a drill or pin or guide wireat corresponding patient-specific insertion points and orientationsrelative to a selected anatomic or reverse axis for the specificpatient. The patient-specific instruments can include guiding ororientation formations and features for guiding the implantation ofpatient-specific or off-the-shelf implants associated with the surgicalprocedure. The geometry, shape and orientation of the various featuresof the patient-specific instruments, as well as various patient-specificimplants and bone grafts, if used, can be determined during thepre-operative planning stage of the procedure in connection with thecomputer-assisted modeling of the patient's anatomy. During thepre-operative planning stage, patient-specific instruments, custom,semi-custom or non-custom implants and other non-custom tools, can beselected and the patient-specific components can be manufactured for aspecific-patient with input from a surgeon or other professionalassociated with the surgical procedure.

Referring to FIGS. 1-2, a prior art reverse shoulder implant 10 isillustrated. The reverse shoulder implant 10 includes a humeral stem 12,a humeral tray 14, a humeral bearing 16, a glenosphere 18 and abaseplate 20 having a plate portion 22 and a central boss 24. Thehumeral stem 12 is implanted in the humeral bone 26 and has a proximalend 28 coupled via a Morse taper connection to a male taper 30 extendingfrom a plate 32 of the humeral tray 14. The glenosphere 18 can bemodular and include a head 34 articulating with the bearing 16 and anoffset double-taper component 36. The double-taper component 36 has afirst tapered portion 38 coupled to a corresponding tapered opening 40of the head 34 and a second tapered portion 42 coupled to the centralboss 24 of the glenoid baseplate 20. A central screw 44 passes throughthe baseplate 20 into the glenoid face 46 of the patient's scapula.Peripheral screws 48 are used to lock the baseplate 20 in the glenoidface 46.

FIG. 3A illustrates using a guiding pin 50 to guide reaming of theglenoid face 46 in reverse shoulder arthroplasty using a reaming device52. FIG. 3B illustrates the guiding pin 50 through a hole 54 drilledthrough the glenoid face 46. The guiding pin 50 is used to guideplacement of a reverse or anatomic implant, as discussed below.

Referring to FIG. 4, a prior art anatomic shoulder implant 56 isillustrated. The anatomic shoulder implant 56 includes a humeral stem58, a glenosphere 60 and a bearing 62 with peripheral pegs 64 and aremovable or non-removable central peg 66.

Referring to FIG. 5, an exemplary patient-specific glenoid guide 68 isillustrated. Patient-specific guide 68 and operation thereof is fullydescribed in U.S. patent application Ser. No. 13/653,868 filed Oct. 17,2012, the entire disclosure of which is hereby incorporated byreference. The patient-specific glenoid guide 68 is configured to guidea guiding pin (such as the guiding pin 50 shown in FIGS. 3A and 3B) andprovide an implant alignment orientation for reverse as well as anatomicshoulder arthroplasty at the surgeon's discretion.

The glenoid guide 68 has an upper (or outer) surface 70 and a lower (orinner) or anatomy-engaging and patient-specific surface 72 thatreferences (substantially as a negative or inverse or mirror) theglenoid face 46 and may include all or a portion of the labrum, i.e.,the peripheral cartilaginous structure that encircles and deepens theglenoid face 46. Alternatively, the labrum can be completely removedsuch that the patient-specific glenoid surface 72 references and mirrorsonly the bone surface of the glenoid cavity or glenoid face 46.Optionally, the glenoid guide 68 can include a peripheral portion orperipheral lip 74 with a corresponding patient-specific peripheralsurface 76 that engages a corresponding peripheral surface or glenoidrim around the scapula of the patient. A first (or anatomic) elongatedtubular drill guide 78 can extend from the upper surface 70 of theglenoid guide 68 at a specific location and along a first axis A that isdetermined and designed according to the pre-operative plan of thepatient to define a patient-specific anatomic alignment axis andinsertion point for a guiding pin 50.

A second (or reverse) elongated tubular drill guide 80 can extend fromthe upper surface 70 of the glenoid guide along a second axis B that isdetermined and designed according to the pre-operative plan of thepatient to define a patient-specific reverse alignment axis andinsertion point for a guiding pin 50. The reverse alignment axis B canhave a predetermined inferior tilt relative to the anatomic alignmentaxis A, such as, for example, a ten-degree inferior tilt. The first andsecond drill guides 78, 80 define corresponding elongated bores forguiding a drill bit and/or inserting an alignment pin or guiding pin 50.Each drill guide 78, 80 can include elongated openings or viewingwindows 82 therethrough. The anatomic drill guide 78 and the reversedrill guide 80 can include corresponding visual and/or tactile markings84, 86 indicating their corresponding functions for easy identificationand to avoid confusion. The markings can be, for example, elevatedlettering using the words ANATOMIC for marking 84 and REVERSE formarking 86. Additionally, marking 88 can be provided with otherpatient-specific information, such as, for example, patientidentification, procedure, etc.

Referring to FIGS. 3A, 3B, and 4, the glenoid guide 68 can be used foranatomic or reverse arthroplasty to drill a hole 54 into the glenoidface 46 through the anatomic or reverse drill guides 78, 80 and insert aguiding pin or other K-wire 50. The guiding pin 50 can be used to guidethe predetermined alignment of the bearing 62 in the glenoid face 46 forimplantation in anatomic arthroplasty. Alternatively, the guiding pin 50can be used to guide the predetermined alignment of the baseplate 20shown in FIG. 2 in the glenoid face 46 for implantation in reversearthroplasty.

Once guiding pin 50 has been inserted into glenoid 46, reaming device 52can be used to ream glenoid 46 to form hole 54 in the glenoid 46. It isimportant to control reaming depth so that bearing 62 or baseplate 20can be properly fitted with hole 54. In addition, it is important tocontrol reaming depth so that the bone can be preserved, and so thatjoint tension can be more accurately controlled. Accordingly, thepresent disclosure provides a patient-specific depth guide 90 thatprevents reaming device 52 from reaming glenoid 46 to too great a depth.

As best shown in FIGS. 6 and 7, depth guide 90 can be formed from ahollow tube 91 including a length L, a width W (outer diameter), and aninner diameter ID. Depth guide 90 can be formed from materials such astitanium, CoCr or steel. Alternatively, depth guide 90 can be formedfrom polymeric materials such as polyethylene, polypropylene,polystryrene, nylon, and polyether ether ketone (PEEK). Inner diameterID is selected to receive guiding wire 50 snugly therein. Accordingly,after guiding pin 50 has been inserted into glenoid 46 and beforereaming has begun, depth guide 90 can be placed over guiding wire 50 andmoved to abut glenoid 46.

Depth guide 90 includes a first end 92 configured to abut glenoid 46,and a second end 94 configured to abut a surface within reamer 52. Depthguide 90 is preferably tubular or cylindrical in shape, but any shapemay be used without departing from the scope of the present teachings solong as depth guide 90 may be received within reaming device 52. Anouter surface 93 of depth guide 90 may be smooth, or may be formed toinclude apertures (not shown) that reduce the amount of materialrequired to form depth guide 90.

Referring to FIGS. 8 and 8A, it can be seen that reaming device 52includes an elongate recess 96 that extends from reaming tool 97 into aninterior of a handle 99 of reaming device 52. Elongate recess 96 isconfigured to receive guiding wire 50 and depth guide 90 therein. Inaddition, it can be seen that recess 96 includes a reduced diametersection 98 that defines a shoulder 100. Second end 94 of depth guide 90abuts shoulder 100 during reaming of glenoid 46, and prevents reamingdevice 52 from reaming too great a depth into glenoid 46. Accordingly,depth guide 90 of the present teachings acts to provide a physical stopfor glenoid reaming. More specifically, as reaming device 52 beginscutting into glenoid 46, second end 94 of depth guide 90 will be spacedapart from shoulder 100. Once reaming device 52 has cut to thepatient-specific depth, however, second end 94 of depth guide 90 willabut shoulder 100 and prevent reaming device 52 from cutting anyfurther.

Depth guide 90 can be patient-specific such that a depth of reaming canbe determined preoperatively. In this regard, the length L of depthguide 90 can be determined preoperatively to control reaming depth.Because reaming device 52 includes shoulder 100, reamer 52 is made toreference the patient-specific depth guide 90 such that the cuttingdepth of the reaming device 52 is limited to the patient-specific depthfor both anatomic and reverse glenoid reaming. It should be understood,however, that after the reaming depth has been reached and reamingdevice 52 is removed from guiding wire 50, the surgeon may inspect hole54 formed by reaming device 52. If the surgeon determines that thepatient-specific depth is not satisfactory, depth guide 90 may beremoved from guiding wire 50. Reaming device 52 may then be aligned withguiding wire 50 without depth guide 90, and reaming restarted to thedepth desired by the surgeon intraoperatively.

In another embodiment, a plurality of depth guides 90 having differentlengths may be formed preoperatively. If during the course of reaming itis determined that a selected depth guide 90 prevents reaming to anadequate depth, the depth guide 90 may be removed and replaced byanother depth guide having a shorter length. In this manner, the reamingdepth can still be controlled to prevent over-reaming the glenoid 46.

The foregoing description of the embodiments has been provided forpurposes of illustration and description. It is not intended to beexhaustive or to limit the disclosure. Individual elements or featuresof a particular embodiment are generally not limited to that particularembodiment, but, where applicable, are interchangeable and can be usedin a selected embodiment, even if not specifically shown or described.The same may also be varied in many ways. Such variations are not to beregarded as a departure from the disclosure, and all such modificationsare intended to be included within the scope of the disclosure.

Example embodiments are provided so that this disclosure will bethorough, and will fully convey the scope to those who are skilled inthe art. Numerous specific details are set forth such as examples ofspecific components, devices, and methods, to provide a thoroughunderstanding of embodiments of the present disclosure. It will beapparent to those skilled in the art that specific details need not beemployed, that example embodiments may be embodied in many differentforms and that neither should be construed to limit the scope of thedisclosure. In some example embodiments, well-known processes,well-known device structures, and well-known technologies are notdescribed in detail.

What is claimed is:
 1. A system for reaming a bone, comprising: apatient-specific guiding wire configured to be attached to the bone; atubular depth guide configured to cover at least a portion of thepatient-specific guiding wire, the tubular depth guide including a firstend configured to abut the bone, and a second end opposite the firstend; a reaming device including an elongate recess therein that extendsbetween a reaming tool of the reaming device and an interior of a handleof the reaming device, wherein the elongate recess is configured toreceive each of the guiding wire and depth guide therein, the elongaterecess includes a reduced diameter section that defines a shoulder, andthe shoulder is designed to abut the second end of the tubular depthguide to control a depth to which the bone is reamed.
 2. The system ofclaim 1, wherein a length of the tubular depth guide is patient-specificor corresponds to a specific reaming depth.
 3. The system of claim 1,wherein the tubular depth guide is formed from titanium, CoCr, or steel.4. The system of claim 1, wherein the tubular depth guide is formed fromat least one of polyethylene, polypropylene, polystyrene, nylon, andpolyether ether ketone (PEEK).
 5. The system of claim 1, furthercomprising a guide member for aligning the guiding wire relative to thebone.
 6. The system of claim 5, wherein the guide member includes apatient-specific bone engagement surface.
 7. The system of claim 6,wherein the bone engagement surface is complementary to a surface of thebone to be reamed.
 8. The system of claim 5, wherein the guide memberincludes first guide and a second guide that are configured to align theguiding wire relative to the bone in a first orientation and a secondorientation.
 9. A method for reaming a bone, comprising: attaching aguiding wire to the bone; covering at least a portion of the guidingwire with a tubular depth guide, the tubular depth guide including afirst end configured to abut the bone, and a second end opposite thefirst end; reaming the bone with a reaming device, the reaming deviceincluding an elongate recess therein that extends between a reaming toolof the reaming device and an interior of a handle of the reaming device,wherein the elongate recess is configured to receive each of the guidingwire and depth guide therein, the elongate recess includes a reduceddiameter section that defines a shoulder, and the shoulder is designedto abut the second end of the tubular depth guide to control a depth towhich the bone is reamed.
 10. The method of claim 9, wherein a length ofthe tubular depth guide is patient-specific or corresponds to a specificreaming depth.
 11. The method of claim 9, wherein the tubular depthguide is formed from titanium, CoCr, or steel.
 12. The method of claim9, wherein the tubular depth guide is formed from at least one ofpolyethylene, polypropylene, polystyrene, nylon, and polyether etherketone (PEEK).
 13. The method of claim 9, further comprising placing aguide member relative to the bone before attaching the guiding wire tothe bone, the guide member configured to align the guiding wire relativeto the bone.
 14. The method of claim 13, wherein the guide memberincludes a patient-specific bone engagement surface.
 15. The method ofclaim 14, wherein the bone engagement surface is complementary to asurface of the bone to be reamed.
 16. The method of claim 13, whereinthe guide member includes first guide and a second guide that areconfigured to align the guiding wire relative to the bone in a firstorientation and a second orientation.
 17. A method for reaming a glenoidfor an arthroplasty, comprising: positioning a patient-specific glenoidguide proximate the glenoid, the glenoid guide including a first primarydrill guide extending along a first axis and a second primary drillguide extending along a second axis; selecting one of the first andsecond axes for orienting a guiding wire, and positioning a guiding wirein the glenoid that extends along the selected axis; positioning atubular depth guide over the guiding wire such that a first end of thedepth guide abuts the bone and the guiding wire extends outward from asecond of the depth guide; positioning a reaming device over the guidingwire, and reaming the glenoid along the selected axis, wherein thereaming device includes an elongate recess therein that extends betweena reaming tool of the reaming device and an interior of a handle of thereaming device, the elongate recess is configured to receive each of theguiding wire and depth guide therein, the elongate recess includes areduced diameter section that defines a shoulder, and the shoulder isdesigned to abut the second end of the tubular depth guide to control adepth to which the bone is reamed.
 18. The method of claim 17, wherein alength of the tubular depth guide is patient-specific or corresponds tothe depth to which the bone is reamed.
 19. The method of claim 13,wherein the glenoid guide includes a patient-specific bone engagementsurface.
 20. The method of claim 19, wherein the bone engagement surfaceis complementary to the glenoid.